article: Tom, Bill and Dave lost their backpacks. They are at the lost and found case. The backpacks are the same  , but the things in them are different. Can you help them find the right  backpack?
  Tom: I have a math book and a pencil case in my backpack. There are three pencils, a pen and an eraser in the pencil case.
  Bill: I have a Chinese dictionary, a math book and two notebooks in my backpack.
  Dave: There are two CDs, three picture books in my backpack. My English book is also in it.
question: Bill doesn't have  _  in his backpack.
options: a math book a pencil case two notebooks a Chinese dictionary